Disposable central venous catheter and method of use

ABSTRACT

A catheter composed of a length of flexible tubing composed of nonreactive material permitting protracted intravenous placement during periods of intensive care for intravenous feeding and administration of drugs and for monitoring central venous pressure, the catheter being provided with an electrical conductor extending lengthwise of the tubing and providing an electrode at the distal end positioned for sensing intrathoracic EKG activity unaffected by material discharged from the distal end and additionally providing such intrathoracic EKG activity simultaneously with the monitoring of intravenous pressure.

Grausz June 18, 1974 DISPOSABLE CENTRAL VENOUS CATHETER AND METHOD OFUSE [75] Inventor; Henry Grausz, Larkspur, Calif.

[73] Assignees: Henry and Carol Grausz, as trustees for Michael andBradly Grausz; Edgar Braun, part interest to each [22] Filed: Feb. 16,1972 [21] Appl. No.: 226,835

[52] US. CL... 128/2.06 E, 128/2.05 D, 128/D1G. 4 [51] Int. Cl A6lb 5/04[58] Field of Search 128/2.05 D, 2.05 E, 2.05 F, l28/2.05 R, 2.06 E,2.06 R, 2.1 E, DIG. 4, 348, 349 R, 350 R, 404, 407

[56] References Cited UNITED STATES PATENTS 2,976,865 3/1961 Shipleyl28/2.05 D 3,416,533 12/1968 Fisher et a1. 128/404 3,529,592 9/1970Rockwell l28/2.05 D

3,533,403 10/1970 Weedson l28/2.06E. 3,580,983 5/1971 Jackson 128/2.05 R3,664,347 5/1972 Harmjanz 128/404 3,680,544 8/1972 Shinnick et al.128/348 3,682,162 3/1972 Colyer 128/404 FOREIGN PATENTS OR APPLICATIONS1,937,137 2/1970 Germany l28/2.05 R

OTHER PUBLICATIONS U.S. Catheter & Instrument Corp., 1957 catalog, page8 Primary ExaminerWilliam E. Kamm Attorney, Agent, or Firm-Warreri,Rubin, Brucker & Chickering I [57] ABSTRACT 3 extending lengthwise ofthe tubing and providing an electrode at the distal end positioned forsensing intra- I thoracic EKG activity unaffected by material dischargedfrom the distal end and additionally providing such intrathoracic EKGactivity simultaneously with the monitoring of intravenous pressure.

8 Claims, 6 Drawing Figures DISPOSABLE CENTRAL VENOUS CATHETE AND METHODOF USE Catheters of the character described are inserted into thesuperior vena cava of patients as, for example, in intensive care wardsfor the monitoring and treatment of heart patients or in any situationwhere central venous pressure needs monitoring and intravenous feedingof food or drug administration is required. Examples of clinicalsituations include treatment of patients with an acute myocardialinfraction or patients with shock and myocardial disease of any kind. Insuch cases, it is necessary to determine whether the heart is failing oran arrhythmia occurs, at any time during the first several daysfollowing the heart attack. Such information is reflected in the centralvenous pressure and also by providing and continuous monitoring of EKGactivity. Prevalent causes of death are arrhythmia and heart failure,both of which may require the infusion of different medicines.

EKG activity is normally obtained by electrodes placed on the chest ofthe patient which presents several disadvantages, notably theinterfering with the making of physical examination of the chest areaand the generally poor definition of EKG activity inherent in externalskin body placement of the electrodes, par ticularly in the showing ofthe critically important P waves. A clear showing of the P waves hasdistinct advantages in acute arrhythmia in distinguishingsupraventricular tachycardia from ventricular tachycardia. The best andmost dependable sensing and definition of P waves is obtained eitherinthe esophagus or in the superior vena cava. Placement of electrodes inthe esophagus is both dangerous and impractical, and is likely in itselfto affect undesirable cardiac response. It is, accordingly, a featureand object of the present invention to provide an electrode at thedistal end of the central venous catheter which is so positioned as toaccurately and dependably sense EKG activity with good resolution of Pwaves while at the same time not being affected by the infusion of fluidor'medication from the distal end of the catheter'or by the monitoringof central venous pressure. Normally, the catheter will be inserted intoan anticubital vein and threaded up into the superior vena cava forintrathoracic placement and optir'num sensing of EKG activity. Thecatheter may, of course, also be inserted through a femoral vein orsubclavian vein and, in each instance, the doctor is able to monitor EKGrhythms during insertion to obtain accurate intrathoracic location withthe distal end of the catheter approaching but being kept spaced fromthe heart. Engagement of the distal end of the catheter with the heartis easily and immediately seen in the EKG display.

Another feature of the present invention is that the electrodeplacement, in addition to providing superior EKG display with the entirechest area of the patient free for physical examination, also providesan improved and constant electrical contact with the blood adjacent tothe heart and thereby avoids completely the heretofore common occurrenceof falsely set off alarms. The electrode placement makes the location ofthe distal end of the catheter always apparent which, in turn, increasesthe reliability of central venous pressure records.

A critical and dramatic use of the catheter of the present invention isin the emergency and urgency oc .casioned by a cardiac arrest whererestoration of life,

if it is to be accomplished, must be done in a very short time, up toabout three minutes. In such a situation, the attendant needs toestablish respiration, that is, breathe for the patient; monitor theEKG; and obtain access to the central circulation for administration ofdrugs. A central venous catheter is required. since the medicine mustreach the heart and not be merely injected into an arm or other part ofthe body due to lack of blood circulation. At the same time, acontinuous electrocardiographrecording is required to signal theadministration of the right drugs as conditions change. At present, theprocedure is to hook up an EKG apparatus to the patient with the timeconsuming preparation and placement of the required four electrodes,then inserting a catheterto obtain access to the circulation, andinitiating breathing for the patient. The time required to hook up thefour leads of theEKG apparatus becomes critical. With the catheter ofthe present invention, the obtaining of the EKG display and access tothe central circulation of the patient is effected with one maneuver,viz., the insertion of the catheterwhich may be done in a matter ofseconds. Changes in size and direction of the P waves provide animmediate indication of the desired entrance of the catheter into thethorax.

Instruments have been designed and used for the sensing of EKG activitywithin the superior vena cava and within the chambers of the heartitself. The prior art suggests the use of electrodes on speciallydesigned catheters for use by cardiologists in performing heartcatheterization wherethe distal end of the catheter is manipulated intoand through the chambers and connecting valve of the heart for removalof blood, insertingof dye, measuring EKG activity, and shocking orpacing the heart. See US. Pat. Nos. 3,533,403 and 3,568,660. Thesecatheters are in the nature of special surgical instruments which areinserted into the body for the relatively short period of time requiredto accomplish the specific objective noted. Such catheter instrumentshave not been designed or'constructed for theplacement and use of thepresent catheter, that is, one which may be left in the body over aprotracted period of several days; to provide'simultaneous centralvenous fluid administration and sensing of intrathoracic EKG activity;and simultaneous monitoring of central venous pressure and intrathoracicEKG activity.

V The invention possesses other objects and features of I advantage,some of which of the foregoing will be set forth in the followingdescription of the preferred form of the invention which is illustratedin the drawing accompanying and forming part of this specification. Itis to be understood, however, that variations in the showing made by thesaid drawing and description may be adopted within the scope of theinvention as set forth in the claims.

Referring to said drawing:

FIG. 1 is a pictorial view of the apparatus of the pres ent invention; Ia

FIG. 2 is a fragmentary, cross-sectional view of a catheter constructedin accordance with the present invention;

FIG. 3 is a cross-sectional view taken substantially on the plane ofline 3-3 of FIG. 2;

FIG. 4 is a cross-sectional view taken substantially on the plane ofline 44 of FIG. 2;

The catheter of the present invention is of the disposable centralvenous type and is composed of flexible tubing having a length adaptedto extend into the superior vena cava and composed of nonreactivematerial permitting the catheter to remain in place for a protractedperiod of several days during the course of observation and treatment;an electrical conductor 12 carried by the tubing and extendinglengthwise thereof and being electrically insulated from the interiorand exterior walls 13 and 14 of the tubing; an electrode 16 connected toconductor 12 and mounted at the exterior surface of the tubing adjacentto but spaced from the distal end 17 thereof; and a terminal 18 forconductor 12 adjacent the proximal end 19 of the tubing for connectionby lead 21 to an electrocardiograph 22'.

.The proximal end 19 of the catheter is provided with an adapter 20which is, in turn, connected by a length of tubing 25 to the standardthree-way manual cock valve 23 which has conduit connections to the baseof a manometer tube 24 and to the feed conduit 26 of an I.V. bottle 27.Accordingly, valve 23 may be manually turned between an off position, asecond position connecting the manometer 24 to the catheter for readingof central venous pressure, and a third position connecting the catheterto I.V. bottle 27 for infusing fluid through the catheter into the bloodstream. Medicine may be injected into the catheter by means of a needleinserted directly into the tubing.

In distinction to the prior art, catheter instruments mentioned in theforegoing which can be tolerated by the body for a very brief period,the catheter of the present invention is constructed of nonreactivematerial. Nonreactive material is defined as one which the body does notreject or react to. The preferred material is polyethylene. Two othermaterials, Teflon and Silastic, may also be used. It is essential thatthe present catheter be made of a substance which the body will toleratefor extended periods of time, several days, without causing aninflamatory reaction.

Another critical feature of the present catheter is the location ofelectrode 16. It is essential that this electrode be located on theexterior side 14 of the catheter out of contact with the materialdischarged from the distal end 17 so as to be electrically unaffectedthereby. For the same reason, electrode 16 needs be spaced slightly fromtip 17 so that a droplet of saline or other material will flow away fromthe tip without touching electrode 16 and producing an attendant blip onthe electrocardiogram. The essential feature of the present invention isthat a continuous and accurate EKG display is obtained simultaneouslywith the infusion into the blood stream of fluid from the distal end ofthe catheter. Thus, an instantaneous observation may be made of drugadministration and EKG activity which is of critical importance incertain instances, as in the treatment of cardiac arrest. Similarly,immediate observation of EKG activity is provided with the introductionof all types of I.V. materiaLElectrode 16 should be spaced from tip 17by a distance of about one-eighth inch.

Conductor 12 is here embedded in the wall of tubing 11 and is turned tothe outside surface 14 adjacent dis tal end 17 to provide electrode 16.Alternatively, the outer wall portion may be removed to expose theconductor. In a similar manner, the opposite end of conductor 12 isturned out and electrically connected to the base of terminal 18 securedto the proximal end of the catheter. Terminal 18 is here formed with acircular socket 31 dimensioned for receipt of the conventional pin endon EKG conductor 21 and with a set screw 32 for securing the conductorpin in place. Only a fine wire size is required for conducting the EKGpotential. Embedding of conductor 12 in the catheter wall provides therequired electrical insulation. The requirement of a minimum wire sizeenables the use of the invention with standard size central venouspressure catheters, e.g., 22 gauge and 18 gauge, and in usual catheterlengths.

I claim:

1. In medical apparatus including a central venous catheter, anintravenous feeding supply connected to the proximal end of saidcatheter, and an electrocardiograph, the improvement comprising:

a central venous catheter composed of nonreactive material having a walldefining a longitudinally extending bore and an opening at the distalend of said catheter and bore for fluid flow longitudinally through saidbore toward said distal end and for discharge through said opening;

an electrical conductor carried by and extending lengthwise of said walland being electrically insulated from the exterior surface of said walland said bore;

an electrode connected to said conductor and mounted at said exteriorsurface adjacent to but spaced proximally from said opening; and

a terminal connected to said conductor adjacent said proximal end ofsaid catheter and being connected to said electrocardiograph.

2. An apparatus as defined in claim 1,

said catheter having a length dimensioned for intrathoracic placement ofsaid distal end.

3. An apparatus as defined in claim 1,

a manometer; and

valve means connectingsaid manometer and source to said proximal end ofsaid catheter for selectively providing central venous fluidadministration or central venous pressure determination each whilesimultaneously displaying EKG activity.

4. A central venous catheter for use with medical apparatus including anintravenous feeding supply adapted for connection to the proximal end ofsaid catheter and an electrocardiograph, comprising:

catheter means for insertion through a vein and into the thoracic cavityof a patient but short of the heart and composed of nonreactive materialhaving a wall defining a longitudinally extending bore and an opening atthe distal end of said catheter and bore for fluid flow longitudinallyof said bore toward said distal end and for discharge of fluid throughsaid opening, said catheter having a length for disposing said distalend in the patients thorax;

an electrical conductor carried by and extending lengthwise of said walland being electrically insulated from the exterior surface of said walland said bore;

an EKG electrode connected to said conductor and mounted at saidexterior surface adjacent to but spaced proximally from said opening;and a terminal connected to said conductor adjacent said proximal end ofsaid catheter and being adapted for connection to saidelectrocardiograph. 5. A catheter as defined in claim 4, saidnon-reactive material being polyethylene.

6. A catheter as defined in claim 4, said non-reactive material beingTeflon.

7. A catheter as defined in claim 4, said non-reactive material beingSilastic.

8. A method comprising: inserting into a patients vein the distal end ofa central venous catheter having a longitudinally extend ing bore and anopening at said distal end for fluid flow longitudinally through saidbore toward said distal end and for discharge through said opening,

fluid addition to said blood flow.

1. In medical apparatus including a central venous catheter, anintravenous feeding supply connected to the proximal end of saidcatheter, and an electrocardiograph, the improvement comprising: acentral venous catheter composed of nonreactive material having a walldefining a longitudinally extending bore and an opening at the distalend of said catheter and bore for fluid flow longitudinally through saidbore toward said distal end and for discharge through said opening; anelectrical conductor carried by and extending lengthwise of said walland being electrically insulated from the exterior surface of said walland said bore; an electrode connected to said conductor and mounted atsaid exterior surface adjacent to but spaced proximally from saidopening; and a terminal connected to said conductor adjacent saidproximal end of said catheter and being connected to saidelectrocardiograph.
 2. An apparatus as defined in claim 1, said catheterhaving a length dimensioned for intrathoracic placement of said distalend.
 3. An apparatus as defined in claim 1, a manometer; and valve meansconnecting said manometer and source to said proximal end of saidcatheter for selectively providing central venous fluid administrationor central venous pressure determination each while simultaneouslydisplaying EKG activity.
 4. A central venous catheter for use withmedical apparatus including an intravenous feeding supply adapted forconnection to the proximal end of said catheter and anelectrocardiograph, comprising: catheter means for insertion through avein and into the thoracic cavity of a patient but short of the heartand composed of nonreactive material having a wall defining alongitudinally extending bore and an opening at the distal end of saidcatheter and bore for fluid flow longitudinally of said bore toward saiddistal end and for discharge of fluid through said opening, saidcatheter having a length for disposing said distal end in the patientsthorax; an electrical conductor carried by and extending lengthwise ofsaid wall and being electrically insulated from the exterior surface ofsaid wall and said bore; an EKG electrode connected to said conductorand mounted at said exterior surface adjacent to but spaced proximallyfrom said opening; and a terminal connected to said conductor adjacentsaid proximal end of said catheter and being adapted for connection tosaid electrocardiograph.
 5. A catheter as defined in claim 4, saidnon-reactive material being polyethylene.
 6. A catheter as defined inclaim 4, said non-reactive material being Teflon.
 7. A catheter asdefined in claim 4, said non-reactive material being Silastic.
 8. Amethod comprising: inserting into a patient''s vein the distal end of acentral venous catheter having a longitudinally extending bore and anopening at said distal end for fluid flow longitudinally through saidbore toward said distal end and for discharge through said opening andan externally mounted electrode adjacent to but spaced proximal to saidopening; advancing said catheter in the direction of blood flow in saidvein to position said distal end in the patient''s thorax short of thepatient''s heart and with the patient''s blood flOwing across saidelectrode in advance of said opening; connecting said electrode to anelectrocardiogram; and administering fluid through said catheter to saidblood flow while displaying EKG activity as sensed in the patient''sblood upstream from the point of fluid addition to said blood flow.